Current determinator and indicator.



. SHOENBERG & F. TALCOTT.

CURRENT DETERMINATDH AND INDICATOR.

IVI

APPLICATION FILED AUG. I3. |917.

Patented Jan. I4, 1919,

CURRENT METERMENATUM, AND lllilllli'ltlld'.

tpeclcatilon of Lettera Patent.

raten-teuren, it, rate,

v Application tied August t3, 1917. aerial No. lltlttdtd.

To all 'whom t may concern:

titl

Be it known that we, Mm'ron lil. driemannnc and lFnaNn ',llArioorr, citizens ot the llnited States, residing at San Francisco and Burlingame, in the county ot San Fran cisco and 'San Mateo and State of Calitornia, respectively, have invented certain new and useful improvements in Current Determinators and llndicators, ot which the following is a specihcation.

Uur invention relates to devices tor determinatin the character of electrical currents, whet er alternating or direct, andindicating whether it is ot a certain predetermined maximum Voltage or less.

ln the accompanying drawing, Figures il and are diagrammatic illustrations ot apparatus embodying our invention, in which the indications are recorded upon a suitable record sheet, while Fig. 3 shows a visual indicater; Figs. 2 and t are diagrammatic illustrations ot record cards or sheets that may be employed; and lFig. 6 is an end elevation or the case or housing for our indicator illustrated in lig. 5 and having the record sheets in the torm oit a continuous roll attached to the case,

lttelferring lirst to the 'visual indicator illustrated in liigs. 3 and t, the apparatus comprises a transformer provided with terminals 3, /l which may be connected to the line conductors l, 2 to be tested, a lamp 5 being in series with the primary coil l and a lamp t in the circuit ct the secondary coil 8. The transformer and lamps may be inclosed in a suitahle case or housing having a side or tace itl over which a card or sheet l2 may he placed, so that the lamp 5 will appear through the aperture 5l and the lamp t through the aperture 6a. r.lhe card may be provlded with suitable data, such as indicated, which may be lled in by the me chanic or party making the test.

llt willbe evident to those familiar with electrical phenomena, that the lamp 6 in circuit with the secondary ot the transformer will glow when the terminals 3, t are connected p, to an alternating circuit, while the lamp 5 will remain unlighted because the impedance et the primary 'l' will not permit a sulhcient amount ot current to pass to heat the hlament to incandescence although perf mitting a -magnetiaing current to energize the primary. @n the other hand, it the terminals are connected to a direct currentl source, the lamp 5 will glow, while the lamp 6 will remain unlifghted, since no current will be induced in the secondary coil 8.

ln Fig. 5, we have substituted resistances 5, 6 tor the lamps in the'arrangement of ltig. 3. rlhe record cards or sheets l2a may be in the torm or a roll 1t, secured either inside or outside ot the case or housing which .may also contain the transformer coils and resistances. llt the terminals are connected to a direct current source, the resistance wire 5 will be heated, while no current will be induced in the secondary coil of the tnanslormer; while it the terminals are 'connected to a source et alternatin currentfthe impedance of the primary coil will permitonly a small current to ilow, not sut- .V

tieren tpl` heat the wire 5", the current induced inthe secondary coil 8, however, be-

ing sulicient to heat the resistance wire ti.

The paper sheet l2 is placed directly over the resistance wires and will be burnt or scorched by one or the other resistance wire, thereby recording an indication of the character ot the current dowing in the mains 1, Q. rlhe data designating the place and time may be writ'ten vin the appropriate blanlrs on the record sheet, which 'may then be torn od and a new sheet unrolled.

llnstead et resistance wires, we may employ heating or burning elements which fuse, blow or burn out upon the passage ol' the predetermined current. ln Fig. l, the indicating elements 5 and 6 man be formed oitI a fusible metal which will low or fuse noon the tlow of a certain current, or

of some electrical conductor which will burn out, such as a graphite inlr. ln either case the fusing or burning out ot the element 5 or 6" will produce a scorch or burn upon the. paper sheet l2", placed thereover, the indication appearing upon the top side ot the sheetl in the correspondingl circle adjacent the appropriate designation A. C. or D. The tuse or other destructible conductor may then be replaced and a new record placed in position thereover in readiness lor the' next test.

llt is also trequently desirable to lniow whether the line voltage is ll@ volts or 22@ volts. 'llhis may be indicated by providing lili lllltl an element 16 which is connected directly across the terminals and having in circuit 'therewith a fixed non-inductive resistance 17, which is ,adjusted to permit the element 17 to fuse or burn only when the voltage reaches substantially 220 volts. Upon `the flow of current corresponding to 220 volts, the paper 12" will be scorched within the circle thus designated. Instead of scorching the paper, other markings or indications may be caused upon chemically prepared. paper.

The advantages and usefulness of this invention will be appreciated by electricians, linemen and engineers who are required to connect apparatus to electrical circuits in which current is flowing. It is frequently desirable to determine the character of the current and also which of the two usual voltages is connected to the line conductors. Likewise it is often desirable that the mechanic shall file a record with his report of the work done. rIhis apparatus may be made in Very compact form, if necessary small enou h to be placed in ones ocket. We have escribed several forms or .the purpose of clearly disclosing our invention andthe manner of applying or using it, but desire it to be understood that other modifcations and changes may be made within the scope of our claims and without departing from our invention.

1. Apparatus for determining the character of an electric current having terminals adapted to be connected to electric conductors, comprising devices responsive to the iow of current, one of said devices being in direct connectionv with the terminals and the other device being inductively connected thereto.

' 2. Apparatus for determining the character of an electric current having terminals Aadaptedto be connected to electric conductors, comprising thermally responsive devices, one of said-devices belng connected A conductively with the terminals to respond to a direct current, and another device connected to the terminals to respond inductively to an alternating current.

3. Apparatus for determining the character of anv electric current having terminals adapted to be connected to electric conductors, comprising thermally responsive dememe? vices, one of said devices being connected conductively with the terminals with an 1nterposed impedance to respond to a direct current, and another device connected to the terminals inductively to respond t an alternating current.

4. pparatus-for determining the character of an electric current having terminals adapted to be connected to electric conductors, comprising thermally responsive devices, one of said devices 'being connected conductively with the terminals to respond to a direct currentand another device connected to the terminals to respond inductively to an alternating current, and a inedium superposed upon said devices which is aii'ected by the responsive device.

5. Apparatus for determining the character of an electric current having terminals adapted to be connected to electric conductors, comprising thermally responsive devices, one of vsaid devices being connected conductively with the terminals with an interposed impedance to respond to a direct current, and another device connected to the terminals to respond inductively to an alternating current, and a fibrous sheet adjacent said devices which is chemically changed by the heat of the responsive' device.

6. Apparatus for determining the character of -an electric current having terminals for connection to electric conductors, comprising thermally responsive devices, a transformer having its primary coil connected to the terminals, one of said devices being in circuit with said primary coil, and another of said devices being in circuit with the secondary coil of said transformer.

7 Apparatus for determining the character of an electric current having terminals for connection to electric conductors, comprising thermally responsive devices, a

tures.

MILTON H. SHOENBERG. FRANK TALCOTT.

In testimony whereof we aix our signa- 

